Emergence of new IncHI2 multidrug-resistance plasmids carrying VIM-1 metallo-β-lactamase in Escherichia coli in Norway
Authors: Nachiket P Marathe, Vera Radisic, Francisco Salvà-Serra, Edward R B Moore, Didrik H Grevskott
Journal: The Lancet Microbe (2023)

Carbapenem-resistant Enterobacteriaceae are one of the most substantial threats to human health.1Tacconelli E Carrara E Savoldi A et al.Discovery, research, and development of new antibiotics: the WHO priority list of antibiotic-resistant bacteria and tuberculosis.Lancet Infect Dis. 2018; 18: 318-327Summary Full Text Full Text PDF PubMed Scopus (2857) Google Scholar In 2021, IncHI2 plasmids carrying resistance genes against carbapenems and colistin were detected in Enterobacteriaceae.2Liu Z Hang X Xiao X et al.Co-occurrence of blaNDM-1 and mcr-9 in a conjugative IncHI2/HI2A plasmid from a bloodstream infection-causing carbapenem-resistant Klebsiella pneumoniae.Front Microbiol. 2021; 123709Crossref Scopus (8) Google Scholar In this Correspondence, we show the emergence of new IncHI2 plasmids ranging from 300–385 kb and carrying multiple antibiotic resistance genes (ARGs) and heavy metal resistance genes (HMRGs), including two copies of carbapenemase VIM-1, in Escherichia coli in Norway. We analysed 569 cefotaxime-resistant E coli isolates from raw and treated sewage collected from five sewage treatment plants in Bergen, Norway, over a period of 19 months (August, 2020, to February, 2022) for phenotypic antibiotic resistance. Five multidrug-resistant E coli strains (appendix p 2) carrying VIM-1, based on Illumina MiSeq sequencing, were detected only in the influents and effluents of the treatment plant receiving hospital sewage. Four of the five strains (ie, 7–390, 8–386, 8–387, and 8–388) belonged to sequence type 536 and were clonally related based on single nucleotide polymorphism analysis, whereas the fifth strain (ie, 3–349)3Grevskott DH Ghavidel FZ Svanevik CS Marathe NP Resistance profiles and diversity of β-lactamases in Escherichia coli strains isolated from city-scale sewage surveillance in Bergen, Norway mimic clinical prevalence.Ecotoxicol Environ Saf. 2021; 226112788Crossref PubMed Scopus (13) Google Scholar belonged to sequence type 635. Complete genome sequencing with a combination of Oxford Nanopore MinION and Illumina MiSeq sequencing of strain 8–386 showed the presence of 300 585 bp (p8–386_1, CP101587), of strain 7–390 showed the presence of 301 413 bp (p7–390_1, CP101582), and of strain 3–349 showed the presence of 385 171 bp (p3–349_1, CP101332) IncHI2 plasmids carrying two copies of VIM-1 in an identical class 1 integron gene cassette (appendix p 3). These plasmids carry multiple toxin-antitoxin systems, suggesting potential for persistence. Conjugation experiments showed that plasmid p3–349_1 was transferred to a green-fluorescent-protein-tagged E coli strain at a transfer frequency of 2 × 10–5 per recipient cell,4Jutkina J Marathe NP Flach C-F Larsson DGJ Antibiotics and common antibacterial biocides stimulate horizontal transfer of resistance at low concentrations.Sci Total Environ. 2018; 616-617: 172-178Crossref PubMed Scopus (210) Google Scholar showing transfer of resistance against seven different antibiotic classes (appendix p 2). Plasmids p8–386_1 and p7–390_1 do not have the conjugal transfer genes traGHI that are present in plasmid p3–349_1 (appendix p 3), thus explaining the lack of conjugal transfer during repeated experiments. Plasmid p3–349_1 carries 20 unique ARGs, including blaCTX-M-15 and two copies of catA1 and blaVIM-1, whereas plasmids p8–386_1 and p7–390_1 have 15 unique ARGs each (appendix p 5). Furthermore, p3–349_1 carries several HMRGs conferring resistance against arsenic, mercury, tellurium, and copper (appendix p 3), suggesting potential for co-selection of antibiotic resistance. Carbapenem resistance in Norway is low in clinics, with no VIM-1-carrying E coli detected in 2021.5Akselsen PE Andersen CT Caugant DAY Dansie LS Elstrøm P NORM/NORM-VET 2021: usage of antimicrobial agents and occurrence of antimicrobial resistance in Norway.https://munin.uit.no/bitstream/handle/10037/26969/article.pdf?sequence=2&isAllowed=yDate: 2021Date accessed: November 10, 2022Google Scholar However, the emergence of an IncHI2 plasmid carrying VIM-1 carbapenemase with multiple ARGs and HMRGs, and its recurring detection in the treatment plant receiving hospital sewage, suggests a clinical origin and highlights the risks for future dissemination of this plasmid in clinics. We declare no competing interests. NPM conceptualised the study, established the methodology, did the investigation, validated and analysed data, wrote the original draft, reviewed and edited the manuscript, acquired funding, and managed the project. VR and FS-S established the methodology, did the investigation, did the bioinformatic analysis, analysed data, and reviewed and edited the manuscript. ERBM did the investigation, validated data, provided critical inputs, and reviewed and edited the manuscript. DHG established the methodology, did the investigation, analysed data, and reviewed and edited the manuscript. We thank Fereidun Akhoundzadeh (Bergen Vann, Bergen, Norway) for arranging the sampling, Kristine S Akervold (Bergen Kommune, Bergen, Norway) and Sandra McCarley (Bergen Kommune, Bergen, Norway) for their support, and the people from Bergen Kommune (Bergen, Norway) working at the different sewage treatment plants for their help collecting the sewage samples. The Illumina sequencing service was provided by the Norwegian Sequencing Centre (Oslo, Norway), a national technology platform hosted by the University of Oslo and supported by the Functional Genomics and Infrastructure programmes of the Research Council of Norway and the Southeastern Regional Health Authorities. The study was funded by the Research Council of Norway under the Res-Marine project (315266) and the Institute of Marine Research under the Ocean Health Initiative (15495). FS-S and ERBM were supported by the Culture Collection University of Gothenburg project Genomics and Proteomics Research on Bacterial Diversity. The funding agency had no role in the writing or the decision to submit the manuscript for publication. The assembled, complete genome sequences have been submitted to GenBank under the genome accession numbers CP101331–39 (strain 3–349), CP101581–85 (strain 7–390), and CP101586–90 (strain 8–386). The assembled, draft genome sequences have been submitted to GenBank under the genome accession numbers JALDRS000000000 (strain 8–387) and JALDRR000000000 (strain 8–388). Download .pdf (.5 MB) Help with pdf files Supplementary appendix